"Asimov" ) writes:
"Michael Black" bravely wrote to "All" (12 Oct 05 03:15:47)
--- on the heady topic of " Western Electric 302--- dial tone issues"

MB From: (Michael Black)
MB Xref: core-easynews sci.electronics.repair:344872


MB Ken Weitzel ) writes:
wrote:
They didn't have diodes in 1941 of the kind you are thinking about

H. R. Hofmann

Hi...

I stand ready to be corrected, but to the best of my recollection
there were none at all - save mercury vapor tubes...

MB What year did selenium rectifiers come into use?

MB Though I can't remember the name, I thought there was also some
MB other non-tube diode that was in use.

MB There's little reason to expect either in a phone from that vintage,
MB but that doesn't mean there weren't such things.


Michael,

I think there were all kinds of metal/metal-oxide rectifiers in those
early times. They weren't very good but that's all they had. Selenium
was just a more evolved type.

Yes, it was metal-oxide rectifiers that I was thinking of but couldn't
remember the name.

Michael